Method for accessing defect management data

Abstract

A method for accessing defect management data includes reading the required data block in an optical disc when an optical disc drive receives a command, storing data in a first buffer area, caching the required defect management data from a data cache area; otherwise, reading the required defect management data from a defect management area of the optical disc, storing the required defect management data in a second buffer area, checking if the required defect management data is hot defect management data, copying the hot defect management data to the data cache area, replacing the defect data of the first buffer area with the required defect management data, and outputting the data of the replaced first buffer area to expedite the reading process.

1 . A method of accessing defect management data employed by an optical disc drive to read data from an optical disc, the optical disc drive comprising a memory having a plurality of buffer areas allocated therein, the method comprising:
 (1) receiving a command for reading data of a required data block on the optical disc;   (2) reading data in the required data block and storing read data into a first buffer area;   (3) reading defect management data of the required data block that are cached in a data cache area;   (4) replacing defect data in the first buffer area with the defect management data; and   (5) outputting replaced data of the data block in the first buffer area.   
   
   
       2 . The method of  claim 1 , wherein step (3) comprises:
 checking if the data cache area has the defect management data of the required data block stored therein;   when the data cache area has the defect management data of the required data block stored therein, reading the defect management data of the required data block cached in the data cache area, and then proceeding with step (4); and   when the defect management data of the required area are not found in the data cache area, reading the defect management data of the required data block from a defect management area on the optical disc, and then proceeding with step (4).   
   
   
       3 . The method of  claim 2 , wherein after reading the defect management data of the required data block from the defect management area on the optical disc, the method further comprises:
 (3-1) storing the defect management data of the required data block read from the defect management area on the optical disc into a second buffer area.   
   
   
       4 . The method of  claim 3 , wherein after step (3-1) is executed, the method further comprises:
 (3-2) checking if the defect management data in the second buffer area are hot defect management data or not; when the defect management data in the second buffer area are hot defect management data, copying the defect management data in the second buffer area to the data cache area; and when the defect management data in the second buffer area are not hot defect management data, proceeding with step (4) directly.   
   
   
       5 . The method of  claim 4 , wherein a standard of classifying hot defect management data includes a number of times of accessing defect management data, a location of defect management data, or a type of defect management data. 
   
   
       6 . The method of  claim 4 , wherein the hot defect management data stored in the data cache area are appended to data stored in the data cache area such that hot defect management data are accumulated in the data cache area.